Flow characterization systems, such as high performance liquid chromatography systems, gas chromatography systems, and flow-injection analysis systems, are well known in the art. Typically, in a liquid chromatography or a gas chromatography system, a sample is injected into a mobile phase (e.g., a liquid mobile phase or a gaseous mobile phase) being continuously supplied through a chromatography column and a flow detector. One or more sample components are chromatographically separated from each other in the chromatography column, and one or more properties of the separated components are detected in the flow detector. In a typical flow-injection analysis system, a sample is injected into a mobile phase being continuously supplied through a flow detector—directly, without substantial chromatographic separation thereof—and one or more properties of the samples or of components thereof are detected in the flow detector.
Parallel and rapid-serial analysis using high performance liquid chromatography or flow-injection analysis systems are likewise known, and have been applied to screen combinatorial libraries of samples. See, for example, WO 99/51980 and U.S. Pat. Nos. 6,260,407 to Petro et al, and 6,175,409 to Nielsen et al. Numerous types of flow detectors have been developed for application with liquid chromatography and/or flow-injection analysis systems, including for example, optical detectors such as refractive-index detectors, ultraviolet-visual detectors, photodiode array detectors, static-light-scattering detectors, dynamic-light-scattering detectors, and evaporative-light-scattering detectors (also known as evaporative mass detectors), and other types of detectors, such as capillary viscometer detectors, infrared detectors, fluorescence detectors, electrochemical detectors and conductivity detectors. In general, each of these detectors have advantages and disadvantages associated therewith, including for example with respect to sensitivity, universality and robustness. Moreover, most of the known detection systems are not well suited for application beyond traditional flow-characterization platforms. As such, there remains a need in the art for improved flow detectors, including flow detectors having improved sensitivity, universality and robustness, and preferably capable of being applied in connection with new emerging flow-characterization platforms, such as highly parallel liquid chromatography or flow-injection analysis systems. Parallel and serial analysis of samples using gas chromatography systems are also known in the art.
It has been suggested to employ a surface acoustic wave device in combination with a chromatograph in U.S. Pat. No. 5,533,402.
Mechanical oscillators or mechanical resonators, are known in the art as well. Recently, such oscillators have been applied to screen combinatorial libraries of fluid samples (e.g., liquid polymer samples) for various properties of interest, such as viscosity. See U.S. Pat. No. 6,182,499 to McFarland et al.
All patents and printed publications cited herein are hereby incorporated by reference for all purposes.